I am not exactly disappointed, since I have read all of the manga by now, and know that the OAV had no way of surpassing it -- to get to the more interesting bits given how the TV series ended, they would have to introduce Kanako. To introduce Kanako, they would have to go through some of the darkest passages of the manga. And to do all that with just three episodes, it was no way it could be as good.

I am glad I got all the manga early, had I seen the OAV first I might have been discouraged. Sure, it had pretty looking girls (that's what got everyone to Love Hina in the first place), but it can only compress that much story in that period of time.

My favorite parts of the OAV, by the way, is when they brought back Moe-chan. Moe, incidentally, was not in the manga.

It took me quite a bit of will for me to watch the every episode in one go... There were some interesting moments. But really it might not be worth watching in the first place. Read the manga!